The invention relates to solar energy and its practical conversion to mechanical and electrical energy. Solar energy is present in unlimited quantities, is renewable, and pollution free. The large scale conversion of solar energy into mechanical and electrical energy has been hindered by the fact that means to accomplish this have required relatively large structures and/or expensive technology. Among the simplest and most practical means for utilization of thermal solar energy are transparent enclosures which trap solar radiation. These enclosures often referred to as greenhouses have been used successfully to increase the temperatures of gardens, water, and homes. A major limitation of the greenhouse means however is the fact that they have not been adapted for practical conversion of solar energy to electrical and mechanical energy. The present invention provides practical means for the utilization of greenhouses technology for the conversion of solar heat into mechanical and electrical energy. This has been accomplished by an improvement in a differential temperature fluid motor recently invented by the author (U.S. Pat. No. 3,846,984).
The differential temperature fluid motor has described a motor containing a low boiling point fluid which operates through a relatively low differential temperatures between two unit chambers. The warm chamber serves as a heat source and the cold chamber serves as a heat sink. According to Carnot's law the efficiency of the motor is limited by the size of the temperature differences between the heat source and the heat sink. It is, therefore, desirable to increase the temperature difference between the warm and cold chambers. This can be achieved, when direct sunlight is available by combining greenhouse means with the warm chamber of the differential temperature motor. Thus, in this invention a transparent chamber is placed around the warm chamber so that it would trap solar radiation and increase the temperature of the warm chamber. While the temperature of the warm chamber is increased the temperature of the cold chamber may be kept relatively low by a combination of means such as non-transparent barriers which minimize the exposure of the cold chamber to direct solar radiation, evaporation of water from the surfaces of the cold chamber, and immersion of the cold chamber in a relatively cold natural body of water. Thus a relatively large temperature differential between the warm and cold chambers of a differential temperature motor may be inexpensively achieved in ambient environments through solar radiation.
The objectives of the present invention are:
1. to trap solar energy and convert thermal solar energy into mechanical and electrical energy through inexpensive greenhouse means and, PA1 2. to increase the temperature differential between the heat source and heat sink of a temperature differential motor and thus increase the Carnot efficiency of the motor.